An integrated risk assessment of coastal erosion based on fuzzy set theory along Fujian coast, southeast China

Coastal erosion and accumulation has always existed and contributed to the shaping of the present coastlines. However, coastal erosion now is largely intensified due to human activities, causing severe land loss and aggravated financial burden, which is not acceptable. This paper presents an integrated methodology for risk assessment of coastal erosion, aiming at assessing and mapping coastal erosion risk by integrating hazard, exposure and coping capacity to give risk priority and risk mappings to guide coastal erosion risk management. Delphi method, the analytic hierarchy process and the fuzzy set theory were adopted in the study to establish the methodology. Fujian province situated at southeast China was taken as a case study; the final result was effectively supported by the data and provided lots of important information for coastal management. The final risk priority recorded the risk disparities from place to place and ranked them with distinct levels to emphasize those places of higher risk levels which needed urgent mitigation measures for risk reduction, and risk mapping gave a visual and clear impression of risk distribution. The risk priority and mapping was only the first step to coastal erosion management; identification of priority areas, implementation of mitigation measures and regular maintenance and monitoring are advanced jobs need to be done.